Actuator for stringed musical instrument

ABSTRACT

I disclose an actuator or vibrator for a keyboard stringed musical instrument wherein the string is vibrated by adhesion of the string to the actuator. The adhesive effect is obtained by mixing a glazing paste of permanent flexibility in a solvent, absorbing the mixture through a felt damping pad so that it is fully impregnated, then evaporating the solvent, and affixing the thus-impregnated felt pad onto a body portion of the actuator. The glazing paste consists of an inert material, such as talcum, dispersed in a nondrying soft wax, such as a polyamide, plasticized polyethylene wax, or a soft wax of natural origin which also contains a small amount of water to obtain the proper consistency and workability.

United States Patent [72] Inventor Leonard W. Pavia FOREIGN PATENTS fi 3:2 Turnpike, Florham Park. 993,240 1965 Great Britain 84/258 [21] APP] 816,198 Primary Examiner-Richard B. Wilkinson [22] Fi'ed AP '5 1969 Amman! Examiner-John F. Gonzales 5 patented May 4 97. Attorney-James W. Falk [54] ACTUATOR FOR STRINGED MUSICAL INSTRUMENT 3 Claim 3 D a i F r w igs ABSTRACT: I disclose an actuator or vibrator for a keyboard {52] U.S.Cl 84/174, stringed musical instrument wherein the string is vibrated by 34/258, 34/320 adhesion of the string to the actuator. The adhesive effect is [51] Int. Cl G011: 1/00, obtained by mixing a glazing pasta ofpermanem fl ibilit in 3 G: 3/16 solvent, absorbing the mixture through a felt damping pad so Field of Search 84/258, hat it is full impregnated, then evaporating the solvent, and 174143, 247, 1-06, affixing the thus-impregnated felt pad onto a body portion of 1-14, M6 the actuator. The glazing paste consists of an inert material, such as talcum, dispersed in a nondrying soft wax, such as a [56] Rdemnces (med polyamide, plasticized polyethylene wax, or a soft wax of natu UNITED STATES PATENTS ral origin which also contains a small amount of water to ob- 3,423,514 I]! 969 Bierl et al 84/].0IX tain the proper consistency and workability.

50 57 L r W 7/ Patented May 4, 1971 FIG. 2

INVENTOR By LEONARD n4 PAl/M ATTORNEY ACTUATOR FOR STRINGED MUSICAL INSTRUMENT BACKGROUND OF THE INVENTION In my copending application Ser. No. 709,970, filed Mar. 4, I968, now US. Pat. No. 3,525,283, there is disclosed a novel stringed keyboard musical instrument. One important aspect of my novel instrument involves the actuation of the individual strings by a vibrator member that normally rests on the string. The vibrator member includes a resilient portion and then an outer surface, as by a coating, of an adhesive or other material to which the string will adhere.

When the individual key is struck, the vibrator member is lifted. The string adheres to the vibrator member due to the adhesive effect of the outer surface of the vibrator and thus is initially lifted with the vibrator. It is lifted, however, against the inherent tension of the string, which is tuned between a tuning pin and a hitch post or pin, as is usual in such stringed keyboard instruments. As the vibrator is lifted, due to the depression of the key by the player, the string's tension will finally become sufficient to overcome the adhesive force and the string snaps free, thereby being set into vibration.

While a wide variety of different adhesives may be employed in such an instrument, I have found that the choice of adhesive can have very important affects on the tonal quality of the music, on the manner of use of the instrument, and on its adaptability for large-scale commercial utilization where the instrument would be placed in homes and played by the ordinary public, rather than by experts or particularly skilled musicians.

Thus certain adhesives will tend to give a louder tone than others; or a more strident tone; or have a limited durability requiring more frequent replacement.

In a commercially sold instrument intended for general public use, the life expectancy of the adhesive becomes particularly important. Thus it is important that the adhesive employed not lose its tacky or adhesive qualities and also that it not tend to become hard, which would adversely affect the damping action of the vibrator element when it returns to the string. A further desideratum in the adhesive and the vibrator is that it not tend to stick to the strings when the instrument is not in use. In my prior application, the key action was not mounted from the bed of the instrument but instead from a separate plate which in turn was mounted from the actual bed of the instrument by single screws or rods, having oversize washers thereon, to allow the key bed to rock forward and backward slightly. A rocking rod provided a handle for the player to rock the key bed slightly before starting to play the instrument. This serves to lift all the adhesive vibrators off the strings at once and obviate any differences due to some of the vibrators tending to stick to the strings.

While such an arrangement is completely operable and assures that any effects of the vibrators tending to stick to the strings when the instrument is not in use will be obviated, nevertheless it would present an unsatisfactory aspect from the standpoint of general sales to the average music-playing member of the public.

It is accordingly an object of my present invention to provide an adhesive vibrator member having long life, excellent tonal qualities, not subject to hardening of the adhesive, and not subject to sticking on the strings.

It is a further object of my invention to obtain excellent damping characteristics for such a vibrator member.

A still further object of my invention is to provide a method for fabricating such an adhesive vibrator.

SUMMARY OF THE INVENTION These and other objects of my invention are attained in one illustrative embodiment wherein the vibrator is made by having a particular adhesive mixed with a solvent absorbed by a very fine grade of high-quality piano damper felt, sometimes referred to as French felt, and then evaporate the solvent employed so that the adhesive remains impregnated into the felt.

l fabricate the vibrator element from a glazing paste of permanent flexibility consisting of an inert material, such as talcum, dispersed in a nondrying soft wax, such as a polyamide or plasticized polyethylene wax, or a soft wax of natural origin which also contains a small amount of water to obtain the proper consistency and workability.

I dissolve this glazing past or compound in a solvent so as to make the compound or paste thin enough to be absorbed into the felt. The solvent is then allowed to evaporate at room temperature. The past is then firmly impregnated into the felt. The string will tend to cut through the surface film of the paste on the felt and be held adhesively by the paste within the felt.

Further advantages of vibrators in accordance with my present invention are that the touch is always the same, even when a particular note may not have been played for quite a while. Without any tendency of the vibrator to stick to the string, the above-described mechanism for rocking the key bed to separate all of the vibrators from the strings is not required. Further, the vibrator damps effectively without introducing any secondary noise on damping.

Needless to say, the lifeexpectancy of the adhesive is very high and the tonal qualities are excellent. A life test indicates no failure and no lessening of the adhesive actuation after a million operations of the vibrator setting the string into vibration. The string, having a very small surface area actually contacted by the vibrator and being itself under high tension, tends to cut through the surface of the adhesive pad. An advantage of my present invention is that the adhesive is not just an outer surface layer but is in fact diffused within the pad so that the string is held by the adhesive below the surface area of contact.

Further I have found that an adhesive vibrator fabricated in accordance with my present invention does not lose its adhesive nature with time due to collection of dust or other particles on the outer surface. The adhesive outer surface is itself almost tackless to the touch and therefore does not tend to collect such particles which would, of course, destroy the adhesion characteristics of the surface. Further because my present invention utilizes an adhesive body rather than an adhesive surface to grasp the string, the actual character of the outermost surface is not determinative of the operation and life expectancy of my vibrator. Thus I take advantage of the nature of the string and of its cutting tendency which I priorly found to be a factor in the relatively short life of other adhesive actuators.

My instrument has a unique sound since the string is not hit, as in a piano, or actually plucked, as in a harpsichord. The sound may be considered closer to a hand plucked guitar, but with the adhesive vibrator of my present invention I can attain to percent of a piano pianoforte dynamics, i.e., the loudness variation due to differences in the striking of the key. Other adhesives, relying on surface effects and high outer tackiness, do not give this effect.

I have also found that in use a very small amount of the adhesive will be picked up by the string and adhere to it, in effect being transferred to the string from the vibrator. However, since the adhesive is impregnated in the felt this does not detract from the operation of the vibrator but appears to assist in the attainment of the unique sound.

DESCRIPTION OF THE DRAWING FIG. I is a top perspective view of a musical instrument in which my invention may be incorporated;

FIG. 2 is a side view of a key action utilizing my invention and incorporated in the embodiment of FIG. I; and

FIG. 3 is an enlarged representation of a single wire and associated actuation in accordance with my invention.

DETAILED DESCRIPTION Turning now to the drawing, there is depicted in FIG. I a keyboard instrument which may generally be as disclosed in my prior copending application Ser. No. 709, 970, filed Mar.

J. Whit l'he instrument hnsttnlls \\llll|"lli\ the standard elements ofa keyboard Instrument. such M\ the keyboutd l0. ltd ii. a front cover H behind which are locttted the tttntnyt pins 15. seen in H 2. a bottom or base Ll. ilnd side cheeks l6 and i7.

Each string 1.. as seen in i-l(i 2. estends lftllll tt tttntng pin 15. embedded in a tuning pin block 68. ttcrt ss tt hrt'tltze 69 to a second bridge ttnd hitch post. not shown. The sound of the vibrating string may be picked up clectroma tnetically. as :lescribed in my earlier application. or by a sounding board. I have found my vibrator in accordance with my present invention to be unique in the high volume at the sound. thereby pcr- 'nittlng operation with just a sounding board and without arnlification.

The key action employed in this specific illustrative embodirsent is depicted in FIG.1. As there seen a key 50 pivots on a :urved pivot ntil SJ mounted on a fulcrum or pivot bar 54. a )iVOl or fulcrum pin 55 estending up from the bttrS-l through tn enlarged slot in the key 50. as'is itnown in the art. A posiive return ofthe ltey $0 is provided by it pressure spring 57 ositioned between the key 50 and a bracket Sll secured to the my bed Si. The travel ofthe key in pivoting around the pin 55 s limited by a limit finger 60 supported beneath the key 50 ind traveling between a first felt pad 61 mounted on the key red 51 and a second felt pad 62 on a stop bracket 6.) mounted in the key bed in this specific illustrative embodiment. and because ofthe articular adhesive character of the vibrator element. in acordance with my prescnl invention. the key bed SI may be igidly affixed to the bottom or base I: by two key bedmountrtg bloc its 67. at o posite ends ofthe keyboard.

As described i my brior application. the key 50 has atached to its end It an actuator member 70 which normally ests on the string 23. The actuator member may be ofa solid material. such as wood. with a layer 34 of adhesively Imregnated felt. in accordance with my present invention.adtcent the string 23. as best seen in FIG. 3.

The layer 34 is fabricated. in accordance with an aspect of a invention. by mising a glazing paste witha solvent. the aste being of a permanent flexibility and consisting of an ten mineral such as talcum dispersed in a nondryingsoftwatt uch as a polyamide ora plasticized polyethylene watt on soft 'ax of natural origin which also contains a small quantity of in one specific embodiment i used at glazing Pthlt commit.

n2 Sports by vt'ctght ttltaicum 37.! parts by weight oftt polyamide l0 parts by weight ttfwater and I dissolved this paste in a solvent whichyrttty be it petrttltttm distillate such as ttttphthtt or lighter iluidfSpeciftt-ttlly I lit\ solved ID ofthe glazing paste in 20 ml. or 4 cc. of lighter fluid. i have found that from It) to I! g. nl'lhc r ttslt: may tndissolved in 20 ml. or 4 cc. of lighter fluid. the criteria bein tn make the adhesive paste thin enough to be ubsttrbctl into the felt.

The felt which is advantageously a very fine quality piano felt. is used in thicknesses of one-fourth inch and is by llnLll extremely resilient. The felt is immersed in the dissolved PZl\lL' after which the felt is left to dry at room temperature until flit solvent has evaporated. leaving the adhesive intprt- -ntttrtt thro ghout the felt. The felt is then cut to the size and shttpc at the surface of the actuator member 70 and secured to it. an. ht a cement.

Alternatively. the felt may be impregnated with the: dis solved adhesive by iniccting the adhesive into the felt in uttttr tion to or in lieu of just immersing the felt in the dissolved paste. As priorly indicated above in accordance with an :ts t-et ofmy invention the particular adhesive employed Opsrtttcs on the string cutting into the felt and not merely as it surface ctfect. thereby attaining both the desired life characteristics anti the good tonal quality.

lclaim:

I. A vibrator for a stringed musical instrument comprisin .t body member and an adhesive impregnated pad on \itlti member and adapted to engage a string of the instrument in seize and lift the string by adhesion thereby to set it into Vlhll|- tlon. said adhesive pad comprising a piece of felt impregnated with a glazing paste consisting of an inert material dispersed in a nondrylng soft was.

2. A vibrator in accordance with claim I wherein said inert material is talcum and said nondrying soft was is a polymer watt.

3. A vibrator in accordance with claim 2 wherein said polymer watt is a polyamide. 

1. A vibrator for a stringed musical instrument comprising a body member and an adhesive impregnated pad on said member and adapted to engage a string of the instrument to seize and lift the string by adhesion thereby to set it into vibration, said adhesive pad comprising a piece of felt impregnated with a glazing paste consisting of an inert material dispersed in a nondrying soft wax.
 2. A vibrator in accordance with claim 1 wherein said inert material is talcum and said nondrying soft wax is a polymer wax.
 3. A vibrator in accordance with claim 2 wherein said polymer wax is a polyamide. 